Scientists have connected up the world's first computer network protected by “quantum cryptography,” a supposedly unbreakable system that functions off a scheme based on the Heisenberg Uncertainty Principle. For us non-science folk, that means that you can't grab information transmitted through the network without disturbing it somehow, making it easy to detect when somebody's trying to listen in on exchanges. When intruders do try to hack a quantum exchange, photons in the network become scrambled and the rise in the error rate causes that line to get shut down. The exchange is then automatically rerouted through a different node so that the sender and receiver remain in continuous secure contact. Scientists are currently trying to market it to banks and other holders of sensitive information. Is it really unbreakable though? Hard to say. Currently there aren't any methods to fully eavesdrop on information while avoid detection, but researchers at MIT were able to nab about 40% by reading the momentum of photons. I can bet that hackers will be all over this, now that the scientists have more or less issued a direct challenge for them to try. [BBC]